The present disclosure relates to belt attachment jigs configured to attach a belt to a plurality of pulleys by wrapping the belt around the pulleys, and specifically relates to measures for preventing detachment of the belt from the belt attachment jig and damage of the belt.
In general, belt drive systems in which a belt is wrapped around a plurality of pulleys each having a pulley groove on its outer circumferential surface include a tension applying means, such as an auto tensioner, which applies a predetermined tension to the belt after the belt is looped over all of the pulleys.
To avoid the provision of such a tension applying means, there is a belt which, when attached to a plurality of pulleys, is extended in a circumferential direction of a pulley and made to pass over a flange of the pulley. Further, a belt attachment jig for attaching such a belt to a pulley has been suggested.
In the case for example where a belt is wrapped around two pulleys, the belt attachment jig is used in such a manner that the belt is looped over one of the two pulleys, and in this state, remaining part of the belt is wound around the belt attachment jig and the belt attachment jig is attached to the other pulley. In this attachment state, a belt portion located on the rear side of the belt attachment jig in the pulley rotational direction is fitted in the pulley groove, and a belt portion located on the forward side of the belt attachment jig in the pulley rotational direction is bent from the outer circumferential surface of the pulley and led out laterally to a near side of the pulley. Accordingly, part of the belt attachment jig is sandwiched between the belt and the pulley groove. The phrase “near side” as used in this specification refers to the side closer to an operator who is attaching the belt, and the phrase “back side” refers to the side opposite to the side closer to the operator.
The belt attachment jig in this attachment state is moved forward in the pulley rotational direction by rotating the center bolt of the jig-attached pulley with a wrench, etc., to gradually increase the area of the belt which is fitted in the pulley groove, and make the belt completely wrapped around the jig-attached pulley in the end.
For example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2006-300172) discloses a belt attachment jig having a fixing means which fixes the belt attachment jig to a pulley until the belt is fitted in a pulley groove, and a holding surface which holds part of the belt at outside the pulley in an axial direction of the pulley near a pulley flange. The holding surface is flush with the outer circumferential surface of the pulley flange, and holds part of the belt until the belt, which is bent in a belt width direction by rotation of the pulley, is fitted in the pulley groove due to its restoring force.